Po wypłacie kupię nowy termometr, kilka plastrów i małą apteczkę, bo takie rzeczy zawsze się przydają.

It means after payday, after I get paid, or once I’ve received my salary.

In everyday Polish, wypłata can mean:

• salary/paycheck
• the act of being paid
• sometimes payday by extension

So po wypłacie is a very natural way to say after I get paid.

Because the preposition po takes the locative case when it means after.

The basic form is wypłata.
The locative singular is wypłacie.

So:

• wypłata = paycheck / payday
• po wypłacie = after payday

This is a very common pattern:

• po pracy = after work
• po obiedzie = after dinner
• po lekcji = after class

Because Polish usually drops subject pronouns when the verb already shows who is doing the action.

Here, kupię means I will buy. The ending -ę already tells you it is I.

So:

• kupię = I will buy
• ja kupię = I will buy, but with extra emphasis on I

In neutral sentences, Polish normally leaves out ja.

Yes. Kupię is the future tense of the perfective verb kupić.

Polish often forms the future of a perfective verb with just one word:

• kupić = to buy
• kupię = I will buy

This is different from English, where you need will.

Compare:

• kupuję = I buy / I am buying
• kupię = I will buy

Because kupię is better for a single completed action: I’ll buy.

• kupię suggests one finished purchase
• będę kupować suggests an ongoing process, repeated buying, or puts focus on the activity itself

In this sentence, the speaker means a straightforward future result: after getting paid, they will buy these things. So kupię is the natural choice.

Because Polish endings depend on case, gender, and sometimes on words like kilka.

After kupię, direct objects usually go in the accusative:

• nowy termometr → masculine inanimate accusative looks the same as nominative
• mała apteczka → accusative becomes małą apteczkę

But kilka changes things:

• kilka plastrów uses the genitive plural after kilka

So the three parts are different for grammatical reasons:

• nowy termometr
• kilka plastrów
• małą apteczkę

Because kilka normally requires the noun after it to be in the genitive plural.

So:

• plaster = a plaster / bandage
• plastry = plasters
• plastrów = of plasters

After kilka, you use:

• kilka książek = several books
• kilka dni = several days
• kilka plastrów = several plasters

This is one of the important number/quantity patterns in Polish.

Yes. In this sentence, plaster means a medical adhesive bandage or sticking plaster.

Depending on the variety of English:

• British English: plaster
• American English: Band-Aid or bandage in casual speech

Context matters, because plaster in Polish can also mean plaster as a material, but here the medical-shopping context makes the meaning clear.

Yes, it is related to apteka.

• apteka = pharmacy
• apteczka = first-aid kit / medicine box

The ending -czka makes it look like a smaller or more compact item, but apteczka does not mean small pharmacy in normal English. In real usage, it means a first-aid kit or a box/pouch with medical supplies.

So małą apteczkę means a small first-aid kit.

Bo means because.

Yes, you could use ponieważ, but the tone changes a little:

• bo = very common, natural, everyday
• ponieważ = also means because, but sounds a bit more formal or written

So in casual speech, bo is the most natural choice here.

Also, the comma before bo is standard in Polish.

It means such things or things like that.

It refers back to the items just mentioned:

• thermometer
• plasters
• first-aid kit

So the idea is: because things like that always come in handy

Here:

• takie = such / that kind of
• rzeczy = things

Przydają się means are useful, come in handy, or turn out to be useful.

The verb is przydawać się. The się is part of the verb and should not be translated too literally as self.

So:

• To się przydaje. = That comes in handy.
• Takie rzeczy się przydają. = Things like that are useful / come in handy.

In this sentence, zawsze się przydają means they always come in handy.

Because the subject is plural: takie rzeczy = such things.

So the verb must also be plural:

• taka rzecz się przydaje = such a thing comes in handy
• takie rzeczy się przydają = such things come in handy

The ending -ą shows third person plural here.

Polish word order is fairly flexible, but some orders sound more natural than others.

Takie rzeczy zawsze się przydają is very natural. It puts emphasis on the general truth: things like that always come in handy.

You could also hear:

• Takie rzeczy się zawsze przydają
• Zawsze się takie rzeczy przydają — less neutral, more marked

One thing to remember: się usually appears early in the clause and normally does not start the sentence.

So yes, the order can change, but the original version is a very good, natural one.